Method of reducing ores.



FREDERICK M. BEGKET, or NIAGAItA FALLS, NEW YORK.

METHOD OE REDUCING QRES.

Specification of Letters Patent.

Application filed May 11, '1909. Serial'No. 495,217.

Patented Aug. 391909.

To all whom it may concern:

Be it known that I, FREDERICK M. BECKER,

' a subject of the King of Great Britain, residaration of the charge.

ing at Niagara Falls, in the county of N iagara and State of New York,have invented certain new and useful Improvements in Methods of ReducingOres, of which the following is a specification. 1

This vention contemplates the employment as a reducing agent for ores,and more particularly. for the oxid ores of such refractory metals aschromium, tungsten, molyb- .denum and vanadium, of certain borids oralloys or compounds of boron, and particularly the borids of the alkaliearth metals, as calcium borid, for-example, and carbon borid. The useof these reducing agents presents particular advantages in theproduction of metals or afloys which are required to be low I incarbonand silicon, and more particularly in such cases where thepresence of a small roportion of boron in the final roduct is eitheradvantageous or unobjectlonable. For example, chromite may be directlyreduced by an alloy of calcium and boron which may be either a borid ofcalcium or an alloy containing either calcium or boron in excess,

the resulting product being a ferro-chromium which is low in carbon orsubstantially free therefrom. In case the alloy employed contains alsosuch reducing agents as carbon or silicon, or other impurities orconstituents capable of exerting a reducing effect upon the constituentsof the ore under the furnace conditions, these' impuritiesorconstituents are taken into account in the prep- Compounds, and moreparticularly oxidized compounds, of other refractory metals as tungsten,molybdenum and vanadium may be similarly treated. Similarly, chromite orother ore of a refractory metalmay be reduced by carbon borid, bothelements of the reducing agent being oxidized in course of theoperation.

Although carbon is present in. considerable I proportion in the reducingagent, it is found that it shows but little tendency to enter intorobably because the carbon of the initial 0 arge exists in a combinedstate and is therefore not readily dissolved or absorbed by the portionsof the metal first reduced. p

The reducing agents may. be used 1n sub stantially the proportionrequired to combine with the oxygen of the charge, or in somewhatsmaller or greater proportion, depending upon the character of theproduct desired and whether boron is a desirable or noninjuriousconstituent thereof. which it is desired to produce a product low inboron, the ore is preferably employed in In cases in excess on the otherhand, where boron is I unobjectionable oris a desirable constituent ofthe product, a somewhat higher efficiency of operation may be secured byusing a slight excess of the reducing agent or such excess as maycorrespond to the desired boron content of the product. by the presencein the c arge of abase capabe of uniting with the oxid of boronproduced, In case calcium borid 'is used as a reducing agent, this baseis provided wholly "or in part by the oxidation of the calcium, suplemented by such bases. as may be normal y present in the ore. Mostcommercial chronntes contain from 8 to 15 per cent. of alumina and asimilar proportion of mag nesia and to the extent of their resence theseserve the purposes of a basic ux. In case of ores free from basicconstituents, or in case of the deficiency of such constituents,a'suitable basic flux, as lime, is added as reuired, the object beingthe formation of a s ag having a suitable fusing point and a properdegree of fluidity at the working temperature of the furnace. Obviously,an

The 0 eration is facilitated acid flux may be added should theconstitution of the charge'require it for the production of a properslag.

The reduction is preferably carried out in an electric furnace, andwhere a fused metallic roduct low in boron is required, the use of t eelectric furnace, or of a furnace capable of afiording a like high temerature, is probably essential. The electro as may be of carbon, or of arefractory metal or alloy suitably water-cooled, in accordance with theproportion of carbon permissible in the roduct. The lining of thefurnace shou d be chosen with reference to' the composition of the slagto resist so far as possible its corrosive effect. In case very lowercentages of carbon are not required, the furnace may have a hearth orlining of carbon. The oper ation is preferably substantially continuousin haracter, the char e materials being suppli d as required an themolten roducts ta ped from the furnace. The s age. are ad irantageouslyutilized for the production of b0rates,; as for example the borates ofthe alkali metals, or they maybe reduced by carbon in a separateoperation. In the latoccurring in certain claims, I mean v, such tercase the boronsconstituent is recovered,

usuall in the form of an allo with the other reduci le constituents .oft e lag, as for example, analloy of boron wit, silicon, or with siliconand calcium, often in conjunction with a considerable proportion of themetal, as chromium, etc., ori inally reduced in'this form the boron maye repeatedly "utilized" for the reduction.

By the expression refractory metals metals as require the application ofheat to the charge to maintain the reacting temperature for theirreduction by boron or alloys or compounds of boron with production of areduced metal free or substantially free from the unoxidized reducingagent, the

I claim 1. The method of reducing ores of refractory metals, whichconsists in smeltin a reaction not being self-propagating in charac Iter.

charge containing such ore and calcium 3. The method of reducing oies ofrefractory metals, which consists in smelting a charge containing suchore and a borid, thereby producing a metal or alloy and a slagcontaining boron,- and smelting said slag to recover boron therefrom.

4. The method of reducing ores of refractory metals, which consists insmelting a charge containing such ore, a .borid and a basic flux,thereby producing a metal or alloy and a slag containing boron, andsmelting said slag to recover boron therefrom.

5. The method of reducing ores of refractory metals, which consists inelectrically smelting a charge containing such ore and a bori 6. Themethodof reducing ores of refractory metals, which consists inelectrically smeltinga char e containing such ore and a borid of an alkaiearth metal.

In testimony whereof, I aflix my signature in presence of two Witnesses;

FREDERICK M. BECKET. Witnesses:

GEORGE O. VFURNESS, J N. DEINHARDT.

